And fascism is a socialist/syndicalist offshoot in the first place in reaction to the failure of Internatiol socialism at the beginning of WW1
This point of view is definitely something that overstates the degree to which fascism has links to socialism/communism. Fascism certainly was a child of European socialist ideas, but by the same logic it was equally the child of the European right. It was described by its pioneers as a Third Way that took philosophies, tactics, and ideas from a spectrum of existing ideologies. I feel like describing fascism as a product of the failure of socialism during the First World War is wrong in almost every case of actual fascist movements.
Italian fascism didn’t arise because of the failure of socialism to stop the war - it actually arose *in support of the war* and against those who “opposed Italian greatness and the fruits of war.” In the post-war period, it was a veterans association that was discontented because of the lackluster gains of Italy at the expense of her enemies in the Great War, and sought to radically expand and rejuvenate Italy. This was sort of the opposite of “reacting to the failure of international socialism in WW1” and the split that lead to Italian fascism had occurred over Mussolini’s support for the war, not the opposite.
Similarly, early German fascism was a movement of esoteric völkisch circles and veterans organizations that were embittered by the alleged Stab in the Back they received from “Jews, Bolsheviks, and Social-Democrats” and they sought to radically expand Germany and avenge the defeat they suffered in the First World War. While copying methods of organization and some rhetoric for the left (another interesting discussion I won’t go into here), they drew most of their ideological views from the far-right milieu of the former Wilhemine Empire, including anti-semitism and Lebensraum. This didn’t have much to do with the failure of socialism to stop the First World War - again these fascists believed the war was a good thing and their problem was really the conclusion of it.
Then there’s the entire group of fascists intellectuals like Evola and Rosenberg who drew *far* more from weird esotericism and reactionary ideas than they did from socialism. Granted, there was a somewhat revolutionary impulse on the part of early fascisms that were eventually purged, and I can copy-paste a discussion I had elsewhere on the forum about it, but yeah these were more nuanced than simply “offshoot of socialism”
Essentially, fascism didn’t really arise from the failure of socialism at the start of the First World War - it arose from discontent with the end of the war and the radicalization that many went through because of their war time experiences. Additionally, describing it as an offshoot of socialism is a little reductionist and is only telling one part of the larger story.